Datasheet

PSoC Designer IDE Guide, Document # 001-42655 Rev *B 25
Chip-Level Editor
Power Setting [Vdd/SysClock Freq]
This parameter allows you to select the SysClock frequency and nominal operating voltage. Based
upon the SysClock selected, the Internal Main Oscillator (IMO) is set with appropriate calibration set-
tings. Since many internal clocks are derived from the SysClock, you see significant device power-
consumption savings by lowering the SysClock frequency, if the implemented design permits it.
Ref Mux
The Ref Mux source selection is used to control the range and (potential) accuracy of various analog
resources. The reference chosen controls the maximum voltage that is input to a switched capacitor
circuit and output from a switched capacitor circuit. Both the analog ground level and the peak-to-
peak voltage are selected using this parameter. Values specified with the Ref Mux parameter are in
pairs and consist of [AGND level ± full scale]. Keep in mind that selecting Vdd (supply voltage) as a
reference level couples Vdd changes into the AGND input of internal resources. This directly affects
absolute accuracy of measurements. Using the internal bandgap reference results in better accuracy
but may not offer an exact Vdd/2 input reference. Choices of ± full-scale values also offer a number
of options. These full-scale values may be based on the PSoC internal references or on external
input voltages. The ± full scale values present constraints similar to those for AGND in terms of Vdd
variation and absolute range of input/output. Individual design criteria dictate the best selection for
the AGND and ± full-scale values. Further discussion of the analog reference can be found in the
PSoC Technical Reference Manual.
Sleep_Timer
The Sleep_Timer parameter selects the timing of the sleep interrupt, if enabled. When the sleep
interrupt is active, and the processor is in a sleep state, it is awakened at the rate specified with this
parameter. The Watchdog Reset, if enabled, occurs after three rollover events in the sleep timer (if
the Watchdog counter is not reset). A complete discussion of the relation of these two elements is
found in the PSoC Technical Reference Manual.
Supply Voltage
Selects the nominal operating voltage to be either 3.3V or 5V.
SwitchModePump
An integrated switch mode pump circuit is available for operation of the device from very low voltage
sources. The pump requires a few external components and can be configured to automatically turn
on as supply voltage drops. Further discussion of the switch mode pump is found in the PSoC Tech-
nical Reference Manual.
SysClock_Source and SysClock*2 Disable
These parameters allow you to select the 24 MHz system SysClock from an internal or external
source. The SysClock*2 Disable parameter allows the internal 48 MHz clock to be shut off. A com-
plete discussion of system clocking is found in the PSoC Technical Reference Manual.
Timer Clock
Selects the clock source for the 12-bit down counting internal timer (TIMERCLK).
Timer Clock/N
Selects the Timer Clock divider value. The TIMERCLK will be Timer Clock source divided by N.